Production of P-wave Charmed Mesons in Hadronic B Decays

Abstract

Production of even-parity charmed mesons in hadronic B decays is studied. Specifically, we focus on the Cabibbo-allowed decays $\bar{B}\to D^{\ast \ast }\pi$ and ${\bar{D}}_s^{\ast \ast }{D}^{(\ast )}$, where $D^{\ast \ast }$ denotes generically a p-wave charmed meson. While the measured color-allowed decays ${\bar{B}}^0\to D^{\ast \ast +}{\pi }^{-}$ are consistent with the theoretical expectation, the experimental observation of $B^{-}\to D^{\ast \ast 0}{\pi }^{-}$ for the broad $D^{\ast \ast }$ states is astonishing as it requires that the color-suppressed contribution dominates over the color-allowed one, even though the former is $1/m_b$ suppressed in the heavy quark limit. In order to accommodate the data of $\bar{B}\to D^{\ast \ast }{\pi }^{-}$, it is found that $a_2/a_1\approx -0.5$ with a sign opposite to that in $\bar{B}\to D\pi$ decays, where $a_1$ and $a_2$ are the effective Wilson coefficients for color-allowed and color-suppressed decay amplitudes, respectively. The decay constants and form factors for $D^{\ast \ast }$ and the Isgur-Wise functions ${\tau }_{1/2}(\omega )$ and ${\tau }_{3/2}(\omega )$ are extracted from the data of $B\to D^{\ast \ast }\pi$ decays. The Isgur-Wise functions calculated in the covariant light-front quark model are in good agreement with experiment. The neutral modes ${\bar{B}}^0\to D^{\ast \ast 0}{\pi }^0$ for $D^{\ast \ast }=D_0^{\ast }(2400),D_1^{\prime }(2430)$ and ${\bar{B}}^0\to D_1^{\prime 0}(2430)\omega$ are predicted to have branching ratios of order $10^{-4}$ which are also supported by isospin argument. The decay constants of $D_{s0}^{\ast }(2317)$ and $D_{s1}^{\prime }(2460)$ are inferred from the measurements of $\bar{B}\to D_s^{\ast \ast -}D$ to be $58\sim 86$ MeV and $130\sim 200$ MeV, respectively. Contrary to the decay constants $f_{D_0^{\ast }}$ and $f_{D_1^{\prime }}$ which are similar in size, the large disparity between $f_{D_{s0}^{\ast }}$ and $f_{D_{s1}^{\prime }}$ is surprising and unexpected.

27 pages; Sec. IV is updated using the absolute branching ratios of B to D_{s1}(2460)D decays obtained by BaBar

References in corpus (1)

• Heavy Quark Symmetry in Nonleptonic B-Decays to Excited Charmed Mesons

Cited by in corpus (15)

• Strong and radiative decays of the Ds0*(2317) meson in the DK-molecule picture
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• Branching fractions of semileptonic $D$ and $D_s$ decays from the covariant light-front quark model
• Ds0*(2317) and Ds1(2460) mesons in two-body B-meson decays
• Hadronic D decays involving even-parity light mesons
• How to understand the underlying structures of $X(4140)$, $X(4274)$, $X(4500)$ and $X(4700)$
• Nonleptonic two-body B-decays including axial-vector mesons in the final state
• Production of $D_{s0}^{\ast }(2317)$ and $D_{s1}(2460)$ in $B$ decays as $D^{(\ast )}K$ and $D_s^{(\ast )}\eta$ molecules
• Quasi-two-body decays $B_{(s)}\to P{D}_0^{\ast }(2400)\to PD\pi$ in the perturbative QCD approach
• Productions of $D_{s0}^{\ast }(2317)$ and $D_{s1}(2460)$ in $B_{(s)}$ and ${\Lambda }_b({\Xi }_b)$ decays
• The role of $D^{\star \star }$ in $B^{-}\to D_s^{+}{K}^{-}{\pi }^{-}$
• Tensor mesons produced in tau lepton decays
• Probing $D_{s0}^{\ast }(2317)$ in the decays of $B$ to two charmed mesons
• Strong decays of excited $2^{+}$ charmed mesons
• The $B^{+(0)}\to {\bar{D}}^{0(-)}{D}_{s0}^{\ast }(2317{)}^{+}$ decays and the molecular structure of $D_{s0}^{\ast }(2317)$